Simplify to lowest terms. $\dfrac{20}{15}$
What is the greatest common factor (GCD) of 20 and 15? $20 = 2\cdot2\cdot5$ $15 = 3\cdot5$ $\mbox{GCD}(20, 15) = 5$ $\dfrac{20}{15} = \dfrac{4 \cdot 5}{ 3\cdot 5}$ $\hphantom{\dfrac{20}{15}} = \dfrac{4}{3} \cdot \dfrac{5}{5}$ $\hphantom{\dfrac{20}{15}} = \dfrac{4}{3} \cdot 1$ $\hphantom{\dfrac{20}{15}} = \dfrac{4}{3}$